/*
 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package com.oracle.svm.hosted.image;

import static com.oracle.svm.core.util.VMError.shouldNotReachHere;

import org.graalvm.nativeimage.Feature;
import org.graalvm.nativeimage.ImageSingletons;
import org.graalvm.nativeimage.Platform;
import org.graalvm.nativeimage.Platforms;

import com.oracle.svm.core.annotate.AutomaticFeature;
import com.oracle.svm.core.jdk.StringInternSupport;
import com.oracle.svm.hosted.FeatureImpl.BeforeAnalysisAccessImpl;

import jdk.vm.ci.meta.MetaAccessProvider;
import jdk.vm.ci.meta.ResolvedJavaField;

@AutomaticFeature
class StringInternFeature implements Feature {

    @Platforms(Platform.HOSTED_ONLY.class)
    public static ResolvedJavaField getInternedStringsField(MetaAccessProvider metaAccess) {
        try {
            return metaAccess.lookupJavaField(StringInternSupport.class.getDeclaredField("internedStrings"));
        } catch (NoSuchFieldException ex) {
            throw shouldNotReachHere(ex);
        }
    }

    @Override
    public void afterRegistration(AfterRegistrationAccess access) {
        ImageSingletons.add(StringInternSupport.class, new StringInternSupport());
    }

    @Override
    public void beforeAnalysis(BeforeAnalysisAccess a) {
        BeforeAnalysisAccessImpl config = (BeforeAnalysisAccessImpl) a;

        /* Ensure metadata for field is created for later use during image heap writing. */
        getInternedStringsField(config.getMetaAccess());
    }
}
